Games purchased for Google Stadia will not be removed from your library, even if the game is removed from sale.
Talking to IGN and UK press at Google’s offices in London, Google vice president and Stadia boss Phil Harrison addressed concerns that games could be removed from the service and prevent users who have paid for the game without the ability to play.
When posed with the theoretical idea of a publisher pulling support for Stadia after a user having brought one of the company’s games, Harrison responded “Yes, you will still be able to access the game.”
“Now there may be, as we’ve seen in the past, times where the developer or publisher no longer has rights to sell to new players,” he elaborated. “And that means that the game will not be available to new players, but it will continue to be available to existing players.”
Source: IGN.com Google Will Not Remove Games From Your Stadia Library